1. Field of the Invention
The present invention relates to elevator safety devices and, more specifically, relates to a new and improved brake catching device, also referred to in the art as a progressive safety or safety device, for an elevator car or counterweight.
Generally speaking, the elevator safety device of the present invention is of the type comprising a catching or catch roller arranged in a wedge or tapered area which interacts with a free leg member of a guide rail and a brake member, typically a brake plate or pad for braking to standstill an elevator car or a counterweight.
2. Discussion of the Background and Material Information
German Published Patent Application No. 2,604,157, published Aug. 11, 1977, discloses a brake catching device or progressive safety device comprising a guide wedge and a counter jaw member which, during normal operation of the elevator, are guided along a free leg member of a guide rail. The guide wedge is rotatably mounted at its lower end by a guide bolt and is retained at its upper end by an adjustable set of springs. In the event of a malfunction or emergency, a roller holder or mount is upwardly shifted. As a result, a catching roller is upwardly moved by means of a support out of a rest position along the edge of a guide wedge. Upon impact of the catching roller at the guide rail the guide wedge is deflected to one side, specifically to the right in such patent document, and the set of springs is loaded. Upward movement of the catching roll is limited by a braking wedge arranged at the upper end of the guide wedge. When the force exerted by the set of springs exceeds a predetermined value the entire device moves towards the right and the counter jaw bears against the guide rail.
A drawback of this prior art brake catching device or progressive safety is the considerable mechanical construction which is required for the rotatably mounted guide wedge and the set of springs acting upon the upper end of the guide wedge. A further shortcoming of this known brake catching device resides in the fact that prior to placing the same into operation and following the occurrence of a malfunction or emergency situation, there must be carried out an appreciable or critical adjustment of the set of springs and the braking wedge.